Many vehicular door trims including armrests have tolerances to loads applied to the armrest from above. For example, a side plate that extends downward from a back surface (a lower surface) of a top wall of an armrest (a support) may be provided to achieve a tolerance to a load applied to the armrest from above. Such a side plate may be integrally formed with the armrest. The side plate extends downward from a portion of the lower surface of the top wall of the armrest at about middle of the lower surface in a width direction of a vehicle. A lower end of the side plate is fixed to an energy absorbing (EA) member on a back surface (a surface on an outer side of a vehicle compartment) of a lower trim (a lower board), which is a separate component.
In general, an armrest requires a tolerance to a load from above because an occupant of a vehicle may place his or her arm on an upper surface of the armrest. However, it is preferable that the armrest has a lower tolerance so that the armrest bends in a width direction of the vehicle in a side collision to absorb a side impact to protect the occupant. The armrest of the known door trim has not only a tolerance to a load from above but also a tolerance to a side impact. The side plate is integrally formed with the armrest and the upper end of the side plate is fixed to the middle portion of a top wall of the armrest with respect to the width direction of the vehicle. Therefore, the armrest, especially a portion of the armrest around the top wall, is less likely to bend in the width direction of the vehicle sufficiently to absorb the side impact.
Furthermore, the side plate that extends downward from the lower surface of the top wall of the armrest is fixed to the EA member disposed on the outer surface of the lower trim on the outer side of the vehicle compartment. Namely, the side plate, the armrest, and the lower trim (including the EA member) are connected together without any gaps such that they form a closed space. According to this configuration, the tolerance of the armrest improves. As a result, the side impact absorption of the armrest decreases.
Still furthermore, the side plate that is integrally formed with the armrest extends in the direction substantially perpendicular to the direction in which molds used for forming the armrest are opened (corresponding to the width direction of the vehicle when the door trim is installed in the vehicle). Therefore, an undercut process such as sliding needs to be performed for a portion of the door trim between a surface of the armrest on the interior side of the vehicle and the side plate. This makes the forming of the door trim complicated.